Application of microalgae as functional biomaterials for tissue repair and regeneration

Tissue repair and regeneration via advanced tissue engineering strategies offer tremendous translational potential in regenerative medicine. However, challenges remain in engineering large-size tissue constructs and organs and applying them clinically. For instance, various microenvironmental stressors, including excessive inflammation, oxidative stress, infections, nutrient and oxygen deprivation, and waste metabolite accumulation, can compromise cell survival and functionality, impeding tissue regeneration. Microalgae, a diverse group of unicellular photosynthetic microorganisms encompassing prokaryotes and eukaryotes, have been investigated as a functional biomaterial in this context. Rich in bioactive compounds with antitumor, anti-inflammatory, antioxidant, and antimicrobial properties, microalgae provide a unique combination of roles and benefits for medical applications. Microalgae have unique surface characteristics and structures that enable them to absorb and deliver functional molecules, alongside an amenability to genetic engineering for recombinant protein production. Most notably, their ability to generate oxygen through photosynthesis makes them an effective tool for alleviating tissue hypoxia, a common and critical issue in tissue engineering. This review summarizes current strategies for harnessing microalgae in biomedical applications, with a focus on their potential in tissue repair and regeneration. We also discussed the challenges and future directions for advancing their integration into clinical practice. STATEMENT OF SIGNIFICANCE: Advanced tissue engineering strategies hold great promise for repairing and regenerating damaged tissues. However, critical challenges-including limited oxygen and nutrient supply, delayed vascularization, excessive inflammation, and infections-hinder tissue regeneration. Microalgae, a group of unicellular photosynthetic microorganisms, offer innovative solutions due to their rich bioactive compounds, photosynthetic capabilities, unique surface properties, genetic manipulability, and biocompatibility. This review provides a comprehensive overview of current strategies for utilizing microalgae in biomedical applications, with a focus on tissue engineering. It also discusses existing challenges and highlights future directions to advance their clinical translation. By exploring microalgae-based approaches, this review emphasizes their potential to address key hurdles in tissue regeneration and inspire novel biomaterial applications in regenerative medicine.